<!-- Licensed under a BSD license. See license.html for license -->
<!DOCTYPE html>
<html>
  <head>
    <meta charset="utf-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0, user-scalable=yes">
    <title>Three.js - Transparency - AlphaTest</title>
    <style>
    html, body {
        height: 100%;
        margin: 0;
    }
    #c {
        width: 100%;
        height: 100%;
        display: block;
    }
    </style>
  </head>
  <body>
    <canvas id="c"></canvas>
  </body>
<script type="importmap">
{
  "imports": {
    "three": "../../build/three.module.js",
    "three/addons/": "../../examples/jsm/"
  }
}
</script>

<script type="module">
import * as THREE from 'three';
import { OrbitControls } from 'three/addons/controls/OrbitControls.js';
import { GUI } from 'three/addons/libs/lil-gui.module.min.js';

function main() {

	const canvas = document.querySelector( '#c' );
	const renderer = new THREE.WebGLRenderer( { antialias: true, canvas } );

	const fov = 75;
	const aspect = 2; // the canvas default
	const near = 0.1;
	const far = 25;
	const camera = new THREE.PerspectiveCamera( fov, aspect, near, far );
	camera.position.set( 0.5, 1, 0.5 );

	const controls = new OrbitControls( camera, canvas );
	controls.target.set( 0, 0, 0 );
	controls.update();

	const scene = new THREE.Scene();
	scene.background = new THREE.Color( 'white' );

	function addLight( x, y, z ) {

		const color = 0xFFFFFF;
		const intensity = 3;
		const light = new THREE.DirectionalLight( color, intensity );
		light.position.set( x, y, z );
		scene.add( light );

	}

	addLight( - 1, 2, 4 );
	addLight( 1, - 1, - 2 );

	const planeWidth = 1;
	const planeHeight = 1;
	const geometry = new THREE.PlaneGeometry( planeWidth, planeHeight );

	const loader = new THREE.TextureLoader();

	function makeInstance( geometry, color, rotY, url ) {

		const texture = loader.load( url, render );
		texture.colorSpace = THREE.SRGBColorSpace;
		const material = new THREE.MeshPhongMaterial( {
			color,
			map: texture,
			alphaTest: 0.5,
			transparent: true,
			side: THREE.DoubleSide,
		} );

		const mesh = new THREE.Mesh( geometry, material );
		scene.add( mesh );

		mesh.rotation.y = rotY;

	}

	makeInstance( geometry, 'white', 0, 'resources/images/tree-01.png' ); /* threejs.org: url */
	makeInstance( geometry, 'white', Math.PI * 0.5, 'resources/images/tree-02.png' ); /* threejs.org: url */

	class AllMaterialPropertyGUIHelper {

		constructor( prop, scene ) {

			this.prop = prop;
			this.scene = scene;

		}
		get value() {

			const { scene, prop } = this;
			let v;
			scene.traverse( ( obj ) => {

				if ( obj.material && obj.material[ prop ] !== undefined ) {

					v = obj.material[ prop ];

				}

			} );
			return v;

		}
		set value( v ) {

			const { scene, prop } = this;
			scene.traverse( ( obj ) => {

				if ( obj.material && obj.material[ prop ] !== undefined ) {

					obj.material[ prop ] = v;
					obj.material.needsUpdate = true;

				}

			} );

		}

	}

	const gui = new GUI();
	gui.add( new AllMaterialPropertyGUIHelper( 'alphaTest', scene ), 'value', 0, 1 )
		.name( 'alphaTest' )
		.onChange( requestRenderIfNotRequested );
	gui.add( new AllMaterialPropertyGUIHelper( 'transparent', scene ), 'value' )
		.name( 'transparent' )
		.onChange( requestRenderIfNotRequested );

	function resizeRendererToDisplaySize( renderer ) {

		const canvas = renderer.domElement;
		const width = canvas.clientWidth;
		const height = canvas.clientHeight;
		const needResize = canvas.width !== width || canvas.height !== height;
		if ( needResize ) {

			renderer.setSize( width, height, false );

		}

		return needResize;

	}

	let renderRequested = false;

	function render() {

		renderRequested = undefined;

		if ( resizeRendererToDisplaySize( renderer ) ) {

			const canvas = renderer.domElement;
			camera.aspect = canvas.clientWidth / canvas.clientHeight;
			camera.updateProjectionMatrix();

		}

		renderer.render( scene, camera );

	}

	render();

	function requestRenderIfNotRequested() {

		if ( ! renderRequested ) {

			renderRequested = true;
			requestAnimationFrame( render );

		}

	}

	controls.addEventListener( 'change', requestRenderIfNotRequested );
	window.addEventListener( 'resize', requestRenderIfNotRequested );

}

main();
</script>
</html>
